Organometallics 1994,13, 2910-2912
2910
Synthesis and Structural Characterization of the p4-S Heterometallic Cluster (qs-CsH4CH3)Fe3Co(p4-S) (CO)11 Wen-Hua Sun,’ Han-Qing Wang, Quan-Fu Zhou, and Shi-Yan Yang State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 73oo00, China
Kai-Bei Yu Chengdu Center of Analysis and Measurement, Chinese Academy of Sciences, Chengdu 610041, China Received April 8, 19940 Summary: The new p4-Sheterometallic cluster (#-C&C H ~ ) F ~ ~ C O ( ~ ~ - Sw ) (aC s synthesized O)~I in high yield by the addition of (#-C.&CHs)Fe(CO)2 (derived from (tfC&CHs)Fe(CO)2Cl) to HFe2Co(ps-S)(CO)p a t room temperature. The cluster waa characterized by elemental analyses, IR, and NMR as well as X-ray diffraction analysis. I t crystallizes in the monoclinic space grou P1121ln, a = 8.259(1) A, b = 12.832(2) A, c = 21.408(3) y = 90.81(l)0, V = 2268.4(6) As, Z = 4, and D, = 1.89 g-cm-? Structure solution and refinement were based on 2367 inde endent reflections with I13.0u(l) (Mo Ku, X = 0.710 73 )and converged a t R = O.0447(Rw= 0.0399). The p4-S cluster is proposed as an example of intermediates in electrophilic addition-substituent elimination, and the existence of its isoelectronic analogues (.PC,&)MoFe&ob~-S) (C0)12and (#-C&CHs) MoFeKo( ~ ~ - S ) ( C Oalso ) I ~is proposed.
Scheme 1
Introduction
Results and Discussion
1
intermediate
I
bl
With the development of transition-metal cluster chemistry, attempts to synthesize heterometallic clusters have received much attention.lV2 The sulfide ligand has been found to promote such metal cluster formation by expanding ita coordination number and stabilizing the resulting transition-metal clusters.28 In our previous work?Jo heterometallic sulfide clusters, Cp*MoFeCo(p3S)(CO)s and Cp*2Mo2Fe(CO),(p&) (Cp* = qs-C5Hs or qS-CgH&H3),were formed in the reaction of Cp*Mo(C0)3C1 with HFe&o(CO)g(ps-S). It was proposed that an electrophilic addition-substituent elimination reaction sequence (Scheme 1)was involved, but attempts to isolate the intermediate Cp*MoFezCo(pr-S)(CO)12failed. However, a new p4-S cluster, (qWfiCHs)FesCo(p4S)(CO)11,could be synthesizedby the reaction of (qs-C&CHs)Fe(CO)&l with HFe&o(CO)g(pa-S). The synthesis and characterization of the title cluster is reported herein aa well as an X-ray crystal structure determination. *Abstract published in Advance ACS Abstracts, June 1,1994. (l)Vahrenkamp,H. In Transition Metal C h e m b t v ; M a w , A., Diemann, E.,Eda.; Verb Chemie: W e i n h e h 1981,p 35. (2)Whitmire, K. H. J. Coord. Chem. B 1988,17,95. (3) Adame, R.D.; Horvath, I. T.;Wang,S. Inorg. Chem. 1986,24,1728. (4)A h , K D.;Babin, J. E.; Tad, M.Inorg. Chem. 1987,26,2807. (5) Seyferth, D.;Henderson, R. S.;Gallagher, M. K. J. Organomet. Chem. 1980,193,C75. (6)Adam, R.D.;Babin, J. E.; Taei, M.Organometallics 1988,7,503. (7) Adame, R.D.;Babm,J. E.; Wang,J.-G.; Wu, W. Inorg. Chem. 1989,
Synthesis. Treatment of (rP-C&CHdFe(CO)&l with HFe&o(CO)s(p3-S) in tetrahydrofuran (THF) at room temperature gave a new p4-S cluster, (qS-CfiCH3)Fe3Co(p4-S)(CO)11. The p4-S cluster was formed by adding the (qS-C&CH3)Fe(C0)2 fragment to the p3-S ligand of HFe&o(CO)g(p&) while the hydride of the latter was lost;ll i.e., nucleophilic attack at the metal chloride by the sulfido anions was involved in the reaction to form the title cluster. Related additions have been carried out to form clusters of higher nuclearity.5-8J2 According to the theory of isolobal relationships,13 the fragment ($-CfiCHs)Fe(C0)2 is an isolobal analogue of Cp*Mo(CO)s. That meam that the cluster (q6-CsH4analogue of C H ~ ) F ~ & O ( ~ ~ - S ) (isCan O )isoelectronic ~~ Cp*MoFe&o(p4-!3)(CO)12. Although p4-S clusters of the latter type have not been synthesized, their existence was implied by the isolation of the title cluster in terms of the isolobal relationships theory. Therefore, the electrophilic addition-aubstituent eliminationprocess propaeed for the reaction of Cp*Mo(CO)&l with HF~~CO(CO)&Q-S) (Scheme 1)isreasonable. The intermediateswith a MoFw cO(p4-s) core are currently being sought. Characterizationof (+-CSE~C&)F~~C~(~~-S) (CO)11. The elemental analysis corresponded to the given formula. The presence of the terminal carbonyl ligands is confirmed by the IR absorptions in the range 1936-2075 cm-l. In the
28,703.
(8) Adame, €2. D. J. Clwter Sci. 1992,3,283.
( 9 ) s W.-H.; ~ ~ W-,
H.-Q.; Y w , S.-Y.; Z ~ O UQ.-F.; , Yu, K.-B.
Polyhedron 1994,13,389. (10)Sun,W.-H.; Yang, S.-Y.; Wmg, H.-Q.; Z ~ O U Q.-F.; , Yu, K.-B. J. Organomet. Chem. 1994,465,263.
(11)Marko, L.J. Organomet. Chem. 1991,213,271. (12)Richter, F.; Vahrenkamp,H. Angew. Chem.,Int. Ed. Engl. 1978, 17,4.44. (13)Hoff”,R.Science 1982,211,995.Hoftinann,R. Angew. Chem., Int. Ed. Engl. 1982,21,711.
0276-7333/94/2313-2910$04.50/0Q 1994 American Chemical Society
Organometallics, Vol. 13, No. 7, 1994 2911
Notes
Table 1. Atomic Coordinates ( X W ) and Isotropic Thermal Parameters (A2 x 1V)
04
c12
010
W
07
Figure 1. ORTEP drawing of (‘r15-C5H4CH3)Fe3Co(rl-S)(C0)ll.
X
V
I
9720(1) 7468(1) 6924(1) 9482(1) 8657(2) 6444(8) 10915(9) 12505(7) 11573(7) 8812(6) 9613(8) 4816(8) 5983(8) 3968(7) 5296(7) 7949(7) 7622(10) 10343(10) 11411(8) 10842(8) 9155(8) 8790(10) 5853(10) 6553(10) 5135(8) 5984(9) 75 28(8) 123 11( 19) 11289(9) 9860(12) 9267(17) 10405(30) 11596(13)
2265( 1) 3564(1) 1563(1) 2349( 1) 2458(1) 1414(7) 317(5) 3684(5) 340(4) 2 193( 5 ) 5404(4) 4314(5) 3857(5) 153416) 1248(5) -574(4) 1789(7) 1115(7) 3142(6) 1090(5) 2218(5) 4690(6) 4023(6) 3737(5) 1543(6) 1376(5) 256(5) 1990(9) 2726(6) 3056(10) 3766(12) 3859(8) 3214(8)
479( 1) 795(1) 855(1) 2393( 1) 1391(1) 281 l(3) 2 145(3) 407(4) 556(3) -843 (2) 807(3) 1567(3) 433(3) 1590(3) -344(2) 1076(3) 2640(3) 2240(3) 440(4) 530(3) -322(3) 801(4) 1264(4) 46(3). 1307(4) 112(3) 993(3) 3396(8) 3040(4) 3245(4) 282 1( 12) 2362(7) 2487 (4)
IP
NMR spectra observed, characteristic resonances are consistent with the structure of the title cluster. In the group of l3C NMR signals at 96.1, 87.5, 87.6, and 112.6 ppm for C&, the small signal a t 112.6 ppm is due to the tertiary carbon (C(13) in Figure 1). The three resonances in the l3C NMR spectrum at 209.5,210.5, and 213.7 ppm correspond to the carbonyl ligands coordinated to one cobalt and two types of iron. Crystal Structure of (~S-CaH4CHs)Fe~Co(~4-S)(C0)ll. Suitable crystals of (t16-CsH4CH3)FeaCo(p4-S)*Equivalent isotropic U defined as one-third of the trace of the orthogonalized Uu tensor. (C0)ll were obtained by slowly lowering the temperature of ita hexane/THF (4/1) solution. The molecular structure Table 2. Selected Bond Lengths (A) and Angles (deg) is illustrated in Figure 1. Final fractional atomic coorCo-Fe( 1) 2.604( 1) Co-Fe(2) 2.594( 1) dinates are listed in Table 1,while selected bond lengths C0-S 2.158(2) 1.783(7) C4(3) and angles with estimated standard deviations are collected 1.777(7) 1.784(6) Cd(4) C4(5) in Table 2. Fe( 1)-Fe(2) 2.603(1) Fe( 1 ) s 2.155(2) The molecule consists of an equilateral triangle of two 1.777(8) 1.799(8) Fe(l)-C(6) Fe(l)-C(7) 1.789(7) Fe(2)S 2.153(2) Fe(l)-C(8) iron atoms and one cobalt atom with a mean M-M bond 1.766(7) Fe(2)-C( 10) 1.786(7) ~e(2)-~(9) length of 2.60 A and a mean M-M-M angle of 60°. A Fe(2)-C(11) 1.781(7) Fe(3)S 2.256(2) six-electron-donating sulfur atom bridges the three metals 1.767(8) 1.776(9) Fe(3)-C(2) Fe(3)-C(1) with a mean M-S bond length of 2.15 A and is also attached 60.l( 1) Fe(1)Xo-S Fe( l)-Co--Fe(2) 52.8(1) to a terminal (t16-CsH4CH3)Fe(C0)2 group with an Fe(2)-C0-S 52.9( 1) Fe( l ) - C A ( 3 ) 99.7(2) Fe(3)-S bond lengthof 2.25A. ThemeanM-S bondlength 156.7(2) s - c 4 ( 3 ) Fe(2)-Co-C(3) 106.6(3) 155.4(2) F e ( 2 ) < 4 ( 4 ) Fe(l)-C4(4) 99.1(2) of 2.15 A is significantly shorter than the sum of the single 94.8(2) Fe(2)-Cd(5) Fe(l)-C4(5) 93.2(2) bond covalent radii for Fe(3) and S, 2.25 A. The relative 59.q 1) Co-Fe( 1 ) s Co-Fe( 1)-Fe(2) 52.9(1) shortness of the bonds suggests that there is effective Fe(2)-Fe( 1 ) s 52.8(1) Co-Fe( 1)-C(6) 94.9(3) orbital overlap between the sulfur and the Fe(l), Fe(2), 152.4(3) Co-Fe( 1)-C(7) 154.9(3) Fe(2)-Fe( 1)-C(6) and Co atoms. 100.3(2) C e F e ( 1)-C(8) Fe(2)-Fe( 1)-C(7) 98.8(2) 95.7(2) Co-Fe(Z)-Fe( 1) Fe(2)-Fe( 1)-C(8) 60.1(1) While the p4-S ligand acts as a six-electron donor, the 53.1(1) Co-Fe(2)S Fe( 1)-Fe(2)S 52.9(1) terminal carbonyls act as two-electron donors and the 156.3(2) Fe( 1)-Fe(2)-C(9) Co--Fe(2)-C(9) 100.0(2) methylcyclopentadienyl ring contributes five electrons. Co-Fe(2)-C( 10) 98.8(2) Fe( 1)-Fe(2)-C( 10) 99.1(2) Thus the cluster reaches a “closed shell” electronic 96.8(2) Fe(l)-Fe(Z)-C(ll) Co-Fe(2)-C( 11) 152.9(2) 74.3(1) C&Fe(2) C&Fe( 1) 74.0(1) configuration.
Experimental Section All operations were carried out under an atmosphere of dinitrogen on a standard Schlenk line. Solvents were purified by conventional methods and distilled under dinitrogen prior to use. NMR spectra were obtained with a Bruker AM 400 NMR spectrometer. The peak positions are reporteddodield of TMS. The IR spectrum was recorded on a Nicolet 10 DX FT-IR spectrometer. The C and H analyses were carried out with a Carlo-Erba 1106 microanalyzer. (?Wdl&Hs)Fe(C0)2CPand were prepared as described in the literature. HF~~CO(F~-S)(CO)~~~
Fe( 1)S-Fe(2) Fe( l)-S-Fe(3)
74.3( 1) 138.2(1)
C&Fe(3) Fe(Z)S-Fe(3)
136.9(1) 132.3(1)
Preparationof ( b - C ~ ~ , C a ) F e , C o ( p ~ , - s ) ( CAOsolution )ll. of .rl6-CaH&Hs)Fe(C0)2C1(1.1 g, 5 mmol) and HFenCo(fis-S)(CO)e (2.7 g, 6 mmol) in 70 mL of THF was stirred for 6 hat room temperature. The solvent then was removed under reduced pressure. The residue was chromatographed on neutral aluminum oxide (200-300 mesh). Eluting with petroleum ether (3060 “C) removed unreacted HFe&o(ps-S)(CO)e (0.04 g) and (14) Piper, T. S.; Cotton, F. A.; Wilkinson, G. J. Znorg. Nucl. Chem. 1965, 1 , 165.
2912 Organometallics, Vol. 13, No. 7, 1994
Notes
Fea(CO)&-S)s (-0.6 g),” which was a coproduct of HFaCo(prS)(CO)~(purified by extractionwith hexane). Further elution with petroleum ether/THF (3/1)gave a fraction from which the black cluster (rp-Cs)4CHB)FeCoOcl-S)(CO)ll (2.0g, 72%) was obtained. The cluster was not changed when heated in refluxing THF for 4 h. The title cluster was purified by column chromatography. Anal. Calcd for C ~ ~ H ~ C O F ~C,~31.58; O & H, 1.08. Found C, 31.23;H,1.06. IR (KBr pellet): 2075.5 (a), 2048.5 (w), 2004.2 (ve),1959.8(~),1936.7(s)cm-l. NMR(CDCbSiMe4asaninternal standard, ppm): ‘H2.19 (8, CHS), 4.99,5.26(d, br, C&); IF 13.4 (e, CHd, 87.6-112.6 (m, C&), 209.5,210.5,213.7 (T, CO). Single-Cryrtal X-rayDiffractionAnalysis. A blackcrystal of the title cluster having approximate dimensions of 0.18X 0.20 X 0.52 m m was mounted on a R3M/e four-circle diffradometer. Graphite-monochromated Mo Ka radiation (A = 0.710 73A) and a 8/28acan type was used to measure the intensity data in the range 2O < 28 6 45O. T h e unit cell was determined and refined with 24 reflections in 28 range from 6.12 to 24.17O. Crystal data for (rp-Cs)4CHa)FesCoOcl-S)(CO)ll: C17H&oFeaOnS7, monoclinic space group P1121/n,a = 8.259(1) A, b = 12.832(2)A,c =
21.408(3) A, y = 90.81(1)’, V = 2268.4(6) AS,2 = 4,D, = 1.89 g.cm4, p(Mo Ka) = 27.42 cm-1, F(O00) = 1271.76. The 2367 independent reflections with Z 3 3.&(1) of 3328 measured were corrected for Lorentz and polarization effects. The structure was solved by the heavy-atom and refined by full-matrix least squares method. Refmement converged at a final R of 0.0447 (Rw = 0.0399,largest ehifwegd 4.2091,with allowancefor the t h e m anisotropy of all non-hydrogen atom. Complex scatteringfactore were taken from the program package SHELXTL,’B as implemented on an Eclipse S 140 computer, which was used for structure solution and refinement. A weightingschemeo = ~l-exp[-5((sinB)/A)*lJ/[d(F) +O.OOOlPl was used in the latter stages of refmement. Table 1 hta atomic positional parameters with estimated standard deviations.
(15) Bard, A.J.; Cowley, A. H.; Leland,J. K.; Thomas,J. N.;Norman, N.C.;Jutzi, P.; Morley, C.P.; Schlueter,E. J. Chem. Soc., Dalton Tram.
(16) Sheldrick, G.M. SHELXTL, An integrated eyrtem for solving, refininganddisplayine~~s~~~fromd~a~ondata~on 6.1). University of Gottingen, Germany, 1986.
1986,1303.
Supplementary Material Availnbla. For (+-C&CHs)Fer Co(p4-S)(CO)11,tables of crystallographic data,complete bond length and angles, atomic parametere and anisotropic thermal parameters (Uvalues) and structures of the complex (6pages). Ordering information is given on any current masthead page. OM940266C
